Self-Assembled Nanocomposite Film with Tunable Enhanced Fluorescence for the Detection of DNA

Abstract

In this study, a simple and environmentally friendly, silver nanocomposite film was prepared via the in situ reduction of silver ions in self-assembled chitosan (CS)/sodium alginate film matrixes. Negatively charged DNA containing the fluorescent intercalator acriflavine (Acf) was assembled on the surface of the silver nanocomposite film, to facilitate the detection of DNA. A tunable fluorescence enhancement was achieved for the Acf in the silver nanocomposite film simply by changing the thickness of the interlayer between the DNA and the silver nanocomposite film. Using the interlayer prepared by an assembly of poly(acrylic acid) and CS, a significant enhancement in the fluorescence of Acf was obtained. Owing to the ability of Acf to intercalate into DNA, this hybrid system with an enhanced Acf fluorescence could be used to monitor the template-independent DNA elongation process in a facile, high-efficiency, label-free fashion.

Preparation of Hybrid Gold/Polymer Nanocomposites and Their Application in a Controlled Antibacterial Assay

“…Advances in nanotechnology have made an impact on many fields of research, including biology and catalysis. − The unique properties of nanoparticles, such as the ability to modify and control their characteristics, and their large surface-to-volume ratios and well-defined size and shape have drawn much attention for various applications . Different types of nanoparticles include quantum dots, − conjugated polymer dots, − metallic nanoparticles, − and carbon dots, which have all shown great utility in biomedical applications. , Compared with nanoparticles based on a single component, hybrid nanocomposites show even greater potential owing to the possibility of combining the diverse functionalities of different individual components. Many therapeutic and diagnostic applications of hybrid nanocomposites have been reported loading fluorescent drugs, dyes, photosensitizers, , and DNA or RNA. , Multifunctional nanocomposites combine different physical, chemical, and biological properties and show potential advantages over conventional techniques in bioimaging and disease treatment. ,, …”

Aggregation-Induced Energy Transfer of Conjugated Polymer Materials for ATP Sensing

“…Electrons delocalize along the π-conjugated backbones of CPs and can amplify changes in fluorescent signals, which is especially valuable for constructing sensitive chemo- or biosensors. Detection mechanisms can be classified into two categories: measuring changes in fluorescence intensity at a single wavelength; − and measuring the change of a ratio of fluorescence at two wavelengths (ratiometric fluorescence). − Ratiometric fluorescence detection is based on fluorescence resonance energy transfer (FRET) between an energy donor and an acceptor. This interaction is strongly dependent on the distance between the energy donor and acceptor and can be altered by analyte interactions leading to variation in the FRET efficiency and corresponding signal output.…”

Fluorescent Platforms Based on Organic Molecules for Chemical and Biological Detection

“…Recognition sites, in the form of molecules including folic acid, RGD, aptamers, and antibodies, have been added to the surface of nanocomposites to induce specific imaging of cells. Owing to the enhanced fluorophore intensity and photostability, our group developed MEF‐based films to detect phenolic compounds, DNA elongation processes, and protein . During the interactions of fluorescent molecules and targets in the system, we observed amplified changes in the fluorescent signal.…”